For decades, the various New England anti-nuclear groups have waged incessant warfare against the Vermont Yankee nuclear plant and Entergy, which bought the plant from a coalition of Vermont utilities in 2002. The outcome of that struggle now lies in the federal court system, where Entergy has already won one signal victory.

It’s important to keep in mind that, leaving the particulars of the Vermont Yankee battle aside, the anti-nukies are fundamentally opposed to nuclear energy in any form whatever. Only old- timers now remember that the Sierra Club was once pro-nuclear, which it viewed as the saving technology that would make the damming of California mountain streams unnecessary.

Interestingly, the Sierra Club, at least, does not totally slam the door on nuclear even today. In its 2006 energy policy statement it said, “While it is possible that a different approach to nuclear power might substantially address these issues, the likelihood is remote given the decades of research and investment already made.”

What different approach to nuclear power might conceivably avoid the environmental issues that caused the Sierra Club’s opposition? To answer that question it’s necessary to review the origins and development of nuclear power, dating back to the 1950s.

That story is ably told in a book published in 2011 by Richard Martin, titled “Super Fuel.” Martin details the long battle between the demanding and acerbic Admiral Hyman Rickover, who wanted nuclear engines based on known technology right now to propel his fleet of submarines, and the gentle visionary Alvin Weinberg, longtime director of Oak Ridge National Laboratory, who envisioned a nationwide fleet of thorium-powered electric plants, using molten fluoride salts as moderator and coolant.

Rickover, a savage bureaucratic infighter, got what he wanted, and in 1972 Weinberg was fired. The nuclear industry put its muscle behind the hugely expensive liquid metal fast breeder reactor. It in turn was shelved in 1984 after Congress spent $8 billion on the Clinch River Breeder without turning a shovelful of dirt.

As Martin puts it, “Light water reactors and their younger cousin, the liquid metal breeder, won out because of technological intransigence rooted in the military origins of the U.S. nuclear program.”

From 1965 to 1969, however, Weinberg’s molten salt reactor experiment had operated successfully, in the later months with thorium-derived U-233 fuel. By 1973, with Weinberg gone, molten salt was rejected, and thorium was dead. Rickover’s uranium-based industrial empire was preserved. Any cheaper, safer and environment-friendly alternative was shelved.

Now, 40 years later, the liquid fluoride thorium reactor (LFTR) is again emerging as one of the six “Generation Four” nuclear power technologies now viewed as most promising alternatives to traditional light water reactors.

Without going too far into technical details, the LFTR would almost certainly produce electricity cheaper than coal, because of lower capital and fuel costs; use a fuel that is in almost inexhaustible supply, both in the U.S. and elsewhere; operate continuously, in baseload or peaking mode, for up to 30 years; be factory-built and deployed in compact 100-megawatt modules close to the end use of the power; contribute nothing to air or water pollution and need no water for operation; safely consume long-lived transuranic waste products from current nuclear fission reactors; produce high-temperature process heat that can make hydrogen fuel for vehicles; and be walkaway safe.

This is not pie in the sky. The physics is sound, and every part of the LFTR has been successfully tested. What has not been accomplished is the efficient integration of all of the technology features into a marketable product.

The reason it has not is the determined opposition of companies that offer competing nuclear technologies: either light water reactors like the current improved version of Vermont Yankee, the AP-1000, or liquid metal fast reactors like the Russian BR-600, or exotic helium-cooled pebble bed reactors under development in China.

Most of the present anti-nuclear groups are so mindlessly opposed to anything nuclear that they’ll probably denounce the LFTR if and when it appears. Still, more rational anti-nuclear groups like the Sierra Club, which is terrified at the menace of global warming, could possibly find in the LFTR the “different approach” that would win their support (and put coal out of business).

John McClaughry, formerly a nuclear reactor physicist, is vice president of the Ethan Allen Institute (www.ethanallen.org).